Зображення сторінки
PDF
ePub

system the generator is used to charge the storage battery, the current going through the usual automatic cutout switch to prevent a reversal of current at such times that the generator is not supplying enough energy to charge the battery. As is true of the diagram presented above, all of the circuits are clearly shown and may be readily followed by any one.

The construction of the various forms of electric lamps used in motor car lighting systems is clearly shown in Fig. 313. The lamp outlined at A is a combination form, designed to use either kerosene or electricity, the former being used only in the event of failure of the latter. The side lamp at B is a neat form, intended to use electricity only. Dash, coil and speedometer lamps are depicted at C. A combination trouble lamp and cigar lighter is shown at D. The trouble lamp at E is an easily portable form and is convenient for use around the power plant, gasoline tank, etc., deriving its current from the regular battery. A combination tail lamp, having red lens at the rear and a white glass at the side to illuminate the number plate, is shown at F. The approved construction of a variable focus electric head lamp is shown at G.

CHAPTER VII

CLUTCH AND GEARBOX FAULTS

Principal Clutch Troubles Outlined—Cone Clutch Construction and Adjust

ment-Cone Clutch Repair-Plate and Disc Clutches-Band ClutchesPlanetary Gearset Repair-Friction Drive Faults and RemediesTroubles in Sliding Gear Transmission.

It is not difficult to locate defects in the power plant, as the symptoms resulting from faulty action of the engine mechanism and the parts of the auxiliary groups are such that can be readily recognized by comparatively inexperienced repairmen. There are a number of points in the power transmission system that may depreciate in service and their faulty action will not be immediately discovered. There may be serious wear in the power transmission elements, such as the gear box and the rear axle, which will mean a serious diminution in the

mount of power delivered to the rear wheels. As these faults are usually of a purely mechanical nature, they are not generally known, and as a rule only show up in a positive manner when a car is overhauled thoroughly.

Principal Clutch Troubles Outlined. The first member of the power transmission system to be considered is the friction clutch in its various forms, and it is important that clutch troubles be readily recognized, as the power, capacity and speed of the entire vehicle will be affected if the clutch action is not as it should be. Considering first the general troubles which are apt to materialize with all types of clutches, we will consider as the most important a too sudden or harsh engagement, which causes “grabbing,”' failure to transmit the entire engine power, lack of capacity due to failure to engage properly and poor or slow release, which results in "spinning." Clutches that employ frictional material as a facing will not act properly if the material becomes worn or if it

is glazed over. Besides the trouble due to defective friction members, there are other portions of the clutch mechanism that demand care and inspection. As the cone clutch is the most common, we will describe the construction of a typical clutch of this nature and then consider the methods of repairing defects that may materialize in service.

Cone Clutch Construction and Adjustment. The cone clutch assembly shown at Fig. 314 is that used on National automobiles and is one that has given excellent service. The female member is machined in the flywheel rim while the male member, from which the clutch type takes its name, is a truncated cone or saucer-shaped

[graphic][merged small][subsumed][merged small]

Fig. 314.—Clutch and Control Pedal Assembly of National Automobile.

member cast of aluminum, which has a friction facing of leather. The clutch cone transmits power by virtue of frictional adhesion with the flywheel rim, this amount of friction being increased by the wedging action due to the angular face of the clutch members. The pressure maintaining the parts in engagement is produced by

[graphic][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed]

Fig. 315.-Sectional View, Showing Gear Box and Clutch Assembly,

Forming Part of Unit Power Plant.

a substantial coil spring carried by the flywheel extension, this spring exerting its pressure against the cone-carrying member and having its reaction absorbed by an anti-friction bearing of the ball form. The power from the clutch cone carrier is transmitted by a double universal joint to the gearbox, placed back of the clutch and about midway on the chassis frame.

The views of the National chassis presented at Fig. 339 will show the relation of the clutch and gear box in the National car very clearly. When it is desired to interrupt the engine drive the clutch release pedal is depressed, this pulling the clutch cone carrier so the cone is pulled away from the female clutch member. In order to prevent "spinning" and make gear shifting easy, as soon as the clutch cone is fully released a friction brake interlocked with the clutch pedal is brought in contact with a small brake drum member, which retards clutch movement. Another form of friction clutch, showing its relation to the gearbox of a unit power plant, is clearly outlined at Fig. 315. This is of Covert manufacture and will be found on a number of 1915 automobiles. When the clutch and gearset are incorporated as a unit the design of the engine is such that the gear box is bolted directly to the engine crankcase in order to obtain a unit power plant. In this cone clutch the spring pressure maintaining contact between the male and female clutch members is produced by four coil springs carried outside of the clutch cone, where they may be easily reached through the clutch case cover when it is necessary to increase their tension.

It will be apparent that as the clutch facing wears and the cone seats itself deeper into the female member that the spring tension may be reduced to some extent. In the clutch shown the spring pressure may be increased as desired by pulling out the split pins that keep the castellated adjusting nuts from turning and screwing each of these members in the same amount, endeavor being made to have the tension of all springs as nearly equal as possible. The clutch springs exert their pressure against the clutch cone at one end and the reaction is taken through the stud to a spider member between the clutch cone and the flywheel, which bears against a ball thrust-bearing carried by the crankshaft extension member bolted to the flywheel, as indicated. When it is desired to release the clutch, the pedal rocks a shaft to which a yoke member is fastened. This yoke member carries rolls which bear against an upturned flange on the clutch cone carrier, which also transmits the power of the engine to the squared end of the primary shaft. The construction of the gear box will be described in proper sequence.

The clutch shown at Fig. 316, A, is used on models B-24 and

« НазадПродовжити »